The invention relates to a gas bag for an airbag module.
In order to adapt gas bags to different requirements, for example to be driver's, front-passenger's or side airbags, it is known to differ the shapes of the gas bags. While a driver's airbag generally has a symmetrical shape, asymmetrical shapes are known for front-passenger's airbags and flat asymmetrical shapes are known for side airbags. DE 195 41 513 A1, for example, discloses a side airbag which has a C-shaped contour. The restraint function of the airbag is thereby restricted in some areas to certain body parts whose support in the event of a crash is essential.
DE 44 34 036 A1 furthermore discloses a side airbag having a gas bag which has an upper and lower gas chamber, the upper gas chamber being larger than the lower one, so that, in the event of a side impact, the thorax and the head region are uniformly intercepted.
Finally, DE 195 46 143 A1 discloses a vehicle passenger restraint device in which a flexible inflated cushion acting as the side bag has the profile of a door with a window cutout. Therefore, in this design, a cutout is present within the outer contour of the side bag at a location at which the airbag is not wanted.
The gas bags mentioned have the disadvantage that when inflated they are restricted in their degrees of freedom by their connection to the gas generator. In spite of the adapted shape of the known gas bags, this may, in certain installation positions of an airbag module, have a negative effect on the passenger's kinematics. For example, for this reason gas bags cannot be mounted on the vehicle roof. If, because of its restricted degrees of freedom, the inflated gas bag cannot follow the movement sequence of the passenger, relative movements between the gas-bag fabric and the passenger occur. This results in grazes on the skin and in excessive loads on various body parts. For example, a fatal extension of the neck may occur.